An Isolable Stannaimine and Its Cycloaddition/Metathesis Reactions with Carbon Dioxide

An N-heterocyclic stannylene :Sn(NONAd) (NONAd = [O(SiMe2NAd)2]2-, Ad = 1-adamantyl), reacts rapidly with 2,4,6-tricyclohexylphenyl azide (TCHP)N3, affording a stannaimine, (NONAd)Sn 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 N(TCHP). Solutions of (NONAd)SnN(TCHP) react immediately with carbon dioxide (CO2) to give a [2+2]-cycloaddition product, which, upon heating, subsequently engages in a metathesis process to give [Sn(NONAd)(mu-O)]2 and the bulky isocyanate, (TCHP)NCO. An isolable stannaimine deoxygenates carbon dioxide to form a dimeric stannaoxane and a new isocyanate.